http://nova.newcastle.edu.au/vital/access/services/Feed ${session.getAttribute("locale")} 5 http://nova.newcastle.edu.au/vital/access/manager/Repository/uon:12837 We consider networks in which two different commodities have to be transported across undirected arcs, subject to a shared capacity on the arcs. For each arc and commodity there is an associated non-linear cost that depends on the amount of the commodity transported across the arc. The aim is to minimize the sum of the costs over all arcs and commodities. Efficient algorithms for solving this problem for two types of objective functions will be presented: in the first the cost depends on the absolute value of the flow and in the second the cost is a quadratic function of the flow. Previous work on multi-commodity flow has concentrated on linear cost problems or tackled non-linear cost problems with Lagrangian relaxation methods and other more general techniques. The algorithms in this paper, on the other hand, provide a very efficient way of dealing with two types of non-linear two-commodity optimal flow problems. 2013-05-01T04:16:43.126Z ]]> http://nova.newcastle.edu.au/vital/access/manager/Repository/uon:6546 Mature mouse oocytes are arrested at metaphase of the second meiotic division. Completion of meiosis and a block to polyspermy is caused by a series of repetitive Ca²⁺ transients triggered by the sperm at fertilization. These Ca²⁺ transients have been widely reported to last for a number of hours but when, or why, they cease is not known. Here we show that Ca²⁺ transients cease during entry into interphase, at the time when pronuclei are forming. In fertilized oocytes arrested at metaphase using colcemid, Ca²⁺ transients continued for as long as measurements were made, up to 18 hours after fertilization. Therefore sperm is able to induce Ca²⁺ transients during metaphase but not during interphase. In addition metaphase II oocytes, but not pronuclear stage 1-cell embryos showed highly repetitive Ca²⁺ oscillations in response to microinjection of inositol trisphosphate. This was explored further by treating in vitro maturing oocytes at metaphase I for 4–5 hours with cycloheximide, which induced nuclear progression to interphase (nucleus formation) and subsequent re-entry to metaphase (nuclear envelope breakdown). Fertilization of cycloheximide-treated oocytes revealed that continuous Ca²⁺ oscillations in response to sperm were observed after nuclear envelope breakdown but not during interphase. However interphase oocytes were able to generate Ca²⁺ transients in response to thimerosal. This data suggests that the ability of the sperm to trigger repetitive Ca²⁺ transients in oocytes is modulated in a cell cycle-dependent manner. 2012-01-30T04:07:42.873Z ]]> http://nova.newcastle.edu.au/vital/access/manager/Repository/uon:705 Schotte and Clum (1982,1987) proposed a model of suicide ideation in which cognitive rigidity (in the presenc eof negative life stress) causes a reduction in problem solving capacity and subsequently leads to hopelessness, which in turn increases the risk for suicide ideation. The aim of the current study was to attempt to improve the model by the addition of a coping variable. The model was tested using a sample 05 85 undergraduate psychology students. the subjects were requested to complete a total of five questionnaires on a once only basis. A new model was developed in which a low level of problem solving confidence and a failure to express emotions combines with the presence of negative life stress to lead to a state of hopelessness, which in turn increases the risk of suicideideation. Results of the study are discussed in terms of the need for a more complex model of suicide ideation which more fully accounts for the effects of different coping strategies on the development of feelings of hopelessness. 2011-12-20T23:20:14.667Z ]]> http://nova.newcastle.edu.au/vital/access/manager/Repository/uon:9638 In this week when it seems the whole world is either mourning or celebrating the arrival of Columbus in the Bahamas some 500 years ago, I have taken some pains to devise a paper which attempts to negotiate, the Atlantic squalls which the Columbus quincentenary has been so successful in generating. Last Wednesday, which was 12 October, Quincentenary Day, the Australian carried a story with the headline, 'Ideology hijacks Columbus anniversary', lamenting the attacks on Columbus, the 'Renaissance man' and a 'weaver's son from Genoa' by the liberal establishment and aggrieved native Americans. 2011-12-07T03:30:05.655Z ]]> http://nova.newcastle.edu.au/vital/access/manager/Repository/uon:6541 Fertilization of mature mouse oocytes triggered highly repetitive Ca²⁺ oscillations lasting 2-3 h. However, immature oocytes generated only two or three oscillations, which ceased within 1 h. Development of repetitive Ca²⁺ transients to sperm occurred late in oocyte maturation and was dependent on cytoplasmic modifications that were independent of cell cycle progression from metaphase I to metaphase II. Immature oocytes released significantly less Ca²⁺ from stores than mature oocytes in response to ionomycin and thapsigargin. Ryanodine had no effect on intracellular Ca²⁺ in maturing oocytes but stimulated an increase in Ca²⁺ in mature oocytes. The ability of ryanodine to increase Ca²⁺ levels was, however, strain-dependent. Preincubation of oocytes with thapsigargin or ryanodine significantly attenuated the normal fertilization Ca²⁺ response, causing a decrease in the number and the rate of rise of the transients. The inhibition of sperm-induced Ca²⁺ transients by ryanodine was independent of its ability to cause an immediate Ca²⁺ increase. Low concentrations of ryanodine had no effect on resting Ca²⁺ levels but inhibited Ca²⁺ oscillations at fertilization. Similarly Ca²⁺ oscillations were blocked in oocytes from a strain of mouse that showed no immediate Ca²⁺ increase with ryanodine. These results suggest that modifications in Ca²⁺ stores and ryanodine-sensitive Ca²⁺ release mechanisms during oocyte maturation play an important role in Ca²⁺ oscillations at fertilization. 2010-07-21T06:00:04.898Z ]]> http://nova.newcastle.edu.au/vital/access/manager/Repository/uon:814 The prologue to the development of educational philosophy outlined recently by Kaminsky (1992) challenged me to think about an epilogue. Is philosophy of education in the 1990s dead in the water or can it contribute dynamically to issues in contemporary research, policy and practice? What I propose to do in this article is to build from Kaminsky's outline of the period 1861-1914 by considering the role of educational philosophy in the period marked by the opposite, the dismantling of modernism in the 1990s. I wish to describe the form of philosophy I see as most appropriate to us now as post-enlightenment pragmatism [pEp] and indicate, in a programmatic style, the ways in which PEP can help educational workers move towards action and power relevant to our new conditions. While this article is exploratory and polemical, the final section refers to specific empirical studies, undertaken over the last 10 years and reported in detail elsewhere that inform the assertions made in earlier sections. 2010-04-27T06:48:33.277Z ]]> http://nova.newcastle.edu.au/vital/access/manager/Repository/uon:2635 Persistent stores support uniform management of data objects regardless of their lifetimes and locations. Such stores typically maintain a self-consistent state even after failure of the host computer system. This property is termed stability, and may be achieved using operations called checkpoints. When objects in the store are modified, or modified objects are accessed, dependencies are created between the modifying processes and the objects. Directed graphs may be used to describe such dependencies. For the persistent store to maintain a consistent state, all dependent entities must be checkpointed together. In this paper we show that hardware support can assist in the construction of stable stores for which stability is based on dependency graphs. We then describe an implementation of such support in the Monads-MM computer. 2010-04-27T06:44:47.612Z ]]> http://nova.newcastle.edu.au/vital/access/manager/Repository/uon:2134 2010-04-27T06:44:17.142Z ]]> http://nova.newcastle.edu.au/vital/access/manager/Repository/uon:2132 2010-04-27T06:44:08.792Z ]]> http://nova.newcastle.edu.au/vital/access/manager/Repository/uon:2133 2010-04-27T06:44:06.663Z ]]> http://nova.newcastle.edu.au/vital/access/manager/Repository/uon:2135 2010-04-27T06:44:04.703Z ]]> http://nova.newcastle.edu.au/vital/access/manager/Repository/uon:2106 2010-04-27T06:43:32.133Z ]]> http://nova.newcastle.edu.au/vital/access/manager/Repository/uon:2641 The act of accessing data objects in a persistent store may result in the creation of state dependencies between the accessing processes and data objects. It is important for the logical integrity of the store that checkpoint or roll-back of all dependent entities (processes or objects) occurs as an atomic action. Reducing the number of dependent entities in the system leads to shortening of the period of suspension of processes during checkpoint and roll-back operations and thus improvement in system efficiency. In this paper we investigate a new approach to the representation of dependencies based on differentiating between dependencies created as a result of read accesses and of write accesses. Using directed graphs to maintain information about dependencies and separately defining the meaning of graph edges for checkpoint and roll-back operations, we show that it is possible to significantly reduce the cascade effects of these operations. 2010-04-27T06:32:29.188Z ]]> http://nova.newcastle.edu.au/vital/access/manager/Repository/uon:2640 In a persistent object store, the acts of modifying data and reading modified data result in the creation of dependencies between the modifying process and the data. Dependencies may be represented using sets, and over time these may grow to encompass many objects and processes. Checkpoint and roll-back operations must propagate to all elements in such a set. This paper presents a new notation for representing dependencies, and shows that differentiating between the dependencies created by modifying data and reading modified data reduces the extent of propagation of checkpoint and roll-back operations. 2010-04-27T06:32:25.800Z ]]> http://nova.newcastle.edu.au/vital/access/manager/Repository/uon:2037 2010-04-27T06:21:09.034Z ]]> http://nova.newcastle.edu.au/vital/access/manager/Repository/uon:2036 2010-04-27T06:21:02.883Z ]]> http://nova.newcastle.edu.au/vital/access/manager/Repository/uon:2056 2010-04-27T06:20:41.403Z ]]> http://nova.newcastle.edu.au/vital/access/manager/Repository/uon:2066 2010-04-27T06:08:54.211Z ]]> http://nova.newcastle.edu.au/vital/access/manager/Repository/uon:2069 2010-04-27T06:08:51.230Z ]]> http://nova.newcastle.edu.au/vital/access/manager/Repository/uon:2083 2010-04-27T06:08:17.252Z ]]> http://nova.newcastle.edu.au/vital/access/manager/Repository/uon:2081 In Australian educational policy debate, advocacy of choice and diversity has come to be linked to support for educational markets and therefore with educational reform and restructuring associated with "economic rationalism." This paper argues that choice and diversity are better conceived within a framework of democratic educational philosophy and policy, and shows that in Australian educational policy development this was the case until the arrival of economic rationalism. The history and outcomes of choice in New South Wales are described. The paper argues that critics of "choice" in the economic-rationalist market context are mistaken to oppose choice as such. Rather, the focus should be on the relationship of choice to basic educational values, such as participation, experimentation, and quality of provision. For these values to be realized in a mutually enhancing way, education systems need to promote sets of real options for students and their families. "Choice" is a secondary concept that emerges within this ethical, political, and professional context. "Markets" are only one putative method for achieving educational participation, diversity, and equality, and should not be conflated with advocacy of quality and equity, diversity and choice. It is suggested that the design of educational systems requires a coherent position on educative learning and on diversity and equity, as well as providing new professional purposes for teachers and collaborative decision-making structures for students and parents. 2010-04-27T06:08:14.901Z ]]> http://nova.newcastle.edu.au/vital/access/manager/Repository/uon:2084 This paper examines whether teachers and parents feel they influence school leaders' work in the policy field of community participation in government schools within the state of New South Wales (NSW), Australia. It reports on the implementation of recent policy initiatives designed to create school/family partnerships. In New South Wales, a move from decentralized school management to shared governance through devolution has placed greater responsibility on the schools and their leaders to gain the active participation of parents and community members and to be more publicly accountable to them. In particular, the Scott Management Review required that each school prepare, in collaboration with school councils, a School Renewal Plan that detailed the school's agreed-upon educational goals and priorities over a 5-year period. In 1994, the Home-School Connections Project was initiated in the Baysview area to explore the nature and effectiveness of home-school linkages. Data were collected through surveys of families and teachers in eight primary schools, interviews with parents and teachers, document analysis, and observation. Findings indicate that a significant number of parents sought ways to participate in their children's education and that many teachers attempted to attract parents into the classroom in ways beyond traditional school-council processes. Teachers were moving toward greater parent participation, though not all wanted to step beyond the traditional role of teacher. Authority was negotiated and shared among different interest groups over different problems and solutions. In summary, effective parent participation enhances the authority of both the home and the school/teacher. It is pointed out that the diversity of opinions need not be threatening; shared meanings are possible and the only way forward. Appendices included a sample report card and an abstract of related research (teacher-parent practices and perceptions of an urban-government school). 2010-04-27T06:08:14.861Z ]]> http://nova.newcastle.edu.au/vital/access/manager/Repository/uon:3702 Participatory research is receiving increasing attention within the broad social science research context. Although there is not a great deal of clarity in the literature regarding what is meant by the term "participatory research", it is essentially a collective term used to describe certain types of research approaches. It has been described as a "methodology for an alternate system of knowledge production" (Reason, 1994:329)rather than a specific research method or prescriptive process. Participative research methodology tends to suggest a compatibility with social work since it appears to reflect come of the fundamental processes and values of the social work profession. This paper aims to introduce the reader to some of the basic tenets of participatory research and to demonstrate its compatibility with social work processes 2010-04-27T05:09:05.690Z ]]>